In one of the most comprehensive studies available, researchers in the Eisenhower Study Group at Brown University's Watson Institute for International Studies looked at the human, economic, social and political costs of the wars in Afghanistan and Iraq, as well as our military actions in Pakistan. Their complete findings are available at costofwar.org. The numbers below are all from their report, which is dated June 2011. When the study sites both conservative and moderate estimates, we've chosen the conservative numbers